1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Suspend support specific for i386/x86-64.
4 *
5 * Copyright (c) 2007 Rafael J. Wysocki <rjw@sisk.pl>
6 * Copyright (c) 2002 Pavel Machek <pavel@ucw.cz>
7 * Copyright (c) 2001 Patrick Mochel <mochel@osdl.org>
8 */
9
10 #include <linux/suspend.h>
11 #include <linux/export.h>
12 #include <linux/smp.h>
13 #include <linux/perf_event.h>
14 #include <linux/tboot.h>
15 #include <linux/dmi.h>
16 #include <linux/pgtable.h>
17
18 #include <asm/proto.h>
19 #include <asm/mtrr.h>
20 #include <asm/page.h>
21 #include <asm/mce.h>
22 #include <asm/suspend.h>
23 #include <asm/fpu/api.h>
24 #include <asm/debugreg.h>
25 #include <asm/cpu.h>
26 #include <asm/cacheinfo.h>
27 #include <asm/mmu_context.h>
28 #include <asm/cpu_device_id.h>
29 #include <asm/microcode.h>
30
31 #ifdef CONFIG_X86_32
32 __visible unsigned long saved_context_ebx;
33 __visible unsigned long saved_context_esp, saved_context_ebp;
34 __visible unsigned long saved_context_esi, saved_context_edi;
35 __visible unsigned long saved_context_eflags;
36 #endif
37 struct saved_context saved_context;
38
39 static void msr_save_context(struct saved_context *ctxt)
40 {
41 struct saved_msr *msr = ctxt->saved_msrs.array;
42 struct saved_msr *end = msr + ctxt->saved_msrs.num;
43
44 while (msr < end) {
45 if (msr->valid)
46 rdmsrl(msr->info.msr_no, msr->info.reg.q);
47 msr++;
48 }
49 }
50
51 static void msr_restore_context(struct saved_context *ctxt)
52 {
53 struct saved_msr *msr = ctxt->saved_msrs.array;
54 struct saved_msr *end = msr + ctxt->saved_msrs.num;
55
56 while (msr < end) {
57 if (msr->valid)
58 wrmsrl(msr->info.msr_no, msr->info.reg.q);
59 msr++;
60 }
61 }
62
63 /**
64 * __save_processor_state() - Save CPU registers before creating a
65 * hibernation image and before restoring
66 * the memory state from it
67 * @ctxt: Structure to store the registers contents in.
68 *
69 * NOTE: If there is a CPU register the modification of which by the
70 * boot kernel (ie. the kernel used for loading the hibernation image)
71 * might affect the operations of the restored target kernel (ie. the one
72 * saved in the hibernation image), then its contents must be saved by this
73 * function. In other words, if kernel A is hibernated and different
74 * kernel B is used for loading the hibernation image into memory, the
75 * kernel A's __save_processor_state() function must save all registers
76 * needed by kernel A, so that it can operate correctly after the resume
77 * regardless of what kernel B does in the meantime.
78 */
79 static void __save_processor_state(struct saved_context *ctxt)
80 {
81 #ifdef CONFIG_X86_32
82 mtrr_save_fixed_ranges(NULL);
83 #endif
84 kernel_fpu_begin();
85
86 /*
87 * descriptor tables
88 */
89 store_idt(&ctxt->idt);
90
91 /*
92 * We save it here, but restore it only in the hibernate case.
93 * For ACPI S3 resume, this is loaded via 'early_gdt_desc' in 64-bit
94 * mode in "secondary_startup_64". In 32-bit mode it is done via
95 * 'pmode_gdt' in wakeup_start.
96 */
97 ctxt->gdt_desc.size = GDT_SIZE - 1;
98 ctxt->gdt_desc.address = (unsigned long)get_cpu_gdt_rw(smp_processor_id());
99
100 store_tr(ctxt->tr);
101
102 /* XMM0..XMM15 should be handled by kernel_fpu_begin(). */
103 /*
104 * segment registers
105 */
106 savesegment(gs, ctxt->gs);
107 #ifdef CONFIG_X86_64
108 savesegment(fs, ctxt->fs);
109 savesegment(ds, ctxt->ds);
110 savesegment(es, ctxt->es);
111
112 rdmsrl(MSR_FS_BASE, ctxt->fs_base);
113 rdmsrl(MSR_GS_BASE, ctxt->kernelmode_gs_base);
114 rdmsrl(MSR_KERNEL_GS_BASE, ctxt->usermode_gs_base);
115 mtrr_save_fixed_ranges(NULL);
116
117 rdmsrl(MSR_EFER, ctxt->efer);
118 #endif
119
120 /*
121 * control registers
122 */
123 ctxt->cr0 = read_cr0();
124 ctxt->cr2 = read_cr2();
125 ctxt->cr3 = __read_cr3();
126 ctxt->cr4 = __read_cr4();
127 ctxt->misc_enable_saved = !rdmsrl_safe(MSR_IA32_MISC_ENABLE,
128 &ctxt->misc_enable);
129 msr_save_context(ctxt);
130 }
131
132 /* Needed by apm.c */
133 void save_processor_state(void)
134 {
135 __save_processor_state(&saved_context);
136 x86_platform.save_sched_clock_state();
137 }
138 #ifdef CONFIG_X86_32
139 EXPORT_SYMBOL(save_processor_state);
140 #endif
141
142 static void do_fpu_end(void)
143 {
144 /*
145 * Restore FPU regs if necessary.
146 */
147 kernel_fpu_end();
148 }
149
150 static void fix_processor_context(void)
151 {
152 int cpu = smp_processor_id();
153 #ifdef CONFIG_X86_64
154 struct desc_struct *desc = get_cpu_gdt_rw(cpu);
155 tss_desc tss;
156 #endif
157
158 /*
159 * We need to reload TR, which requires that we change the
160 * GDT entry to indicate "available" first.
161 *
162 * XXX: This could probably all be replaced by a call to
163 * force_reload_TR().
164 */
165 set_tss_desc(cpu, &get_cpu_entry_area(cpu)->tss.x86_tss);
166
167 #ifdef CONFIG_X86_64
168 memcpy(&tss, &desc[GDT_ENTRY_TSS], sizeof(tss_desc));
169 tss.type = 0x9; /* The available 64-bit TSS (see AMD vol 2, pg 91 */
170 write_gdt_entry(desc, GDT_ENTRY_TSS, &tss, DESC_TSS);
171
172 syscall_init(); /* This sets MSR_*STAR and related */
173 #else
174 if (boot_cpu_has(X86_FEATURE_SEP))
175 enable_sep_cpu();
176 #endif
177 load_TR_desc(); /* This does ltr */
178 load_mm_ldt(current->active_mm); /* This does lldt */
179 initialize_tlbstate_and_flush();
180
181 fpu__resume_cpu();
182
183 /* The processor is back on the direct GDT, load back the fixmap */
184 load_fixmap_gdt(cpu);
185 }
186
187 /**
188 * __restore_processor_state() - Restore the contents of CPU registers saved
189 * by __save_processor_state()
190 * @ctxt: Structure to load the registers contents from.
191 *
192 * The asm code that gets us here will have restored a usable GDT, although
193 * it will be pointing to the wrong alias.
194 */
195 static void notrace __restore_processor_state(struct saved_context *ctxt)
196 {
197 struct cpuinfo_x86 *c;
198
199 if (ctxt->misc_enable_saved)
200 wrmsrl(MSR_IA32_MISC_ENABLE, ctxt->misc_enable);
201 /*
202 * control registers
203 */
204 /* cr4 was introduced in the Pentium CPU */
205 #ifdef CONFIG_X86_32
206 if (ctxt->cr4)
207 __write_cr4(ctxt->cr4);
208 #else
209 /* CONFIG X86_64 */
210 wrmsrl(MSR_EFER, ctxt->efer);
211 __write_cr4(ctxt->cr4);
212 #endif
213 write_cr3(ctxt->cr3);
214 write_cr2(ctxt->cr2);
215 write_cr0(ctxt->cr0);
216
217 /* Restore the IDT. */
218 load_idt(&ctxt->idt);
219
220 /*
221 * Just in case the asm code got us here with the SS, DS, or ES
222 * out of sync with the GDT, update them.
223 */
224 loadsegment(ss, __KERNEL_DS);
225 loadsegment(ds, __USER_DS);
226 loadsegment(es, __USER_DS);
227
228 /*
229 * Restore percpu access. Percpu access can happen in exception
230 * handlers or in complicated helpers like load_gs_index().
231 */
232 #ifdef CONFIG_X86_64
233 wrmsrl(MSR_GS_BASE, ctxt->kernelmode_gs_base);
234 #else
235 loadsegment(fs, __KERNEL_PERCPU);
236 #endif
237
238 /* Restore the TSS, RO GDT, LDT, and usermode-relevant MSRs. */
239 fix_processor_context();
240
241 /*
242 * Now that we have descriptor tables fully restored and working
243 * exception handling, restore the usermode segments.
244 */
245 #ifdef CONFIG_X86_64
246 loadsegment(ds, ctxt->es);
247 loadsegment(es, ctxt->es);
248 loadsegment(fs, ctxt->fs);
249 load_gs_index(ctxt->gs);
250
251 /*
252 * Restore FSBASE and GSBASE after restoring the selectors, since
253 * restoring the selectors clobbers the bases. Keep in mind
254 * that MSR_KERNEL_GS_BASE is horribly misnamed.
255 */
256 wrmsrl(MSR_FS_BASE, ctxt->fs_base);
257 wrmsrl(MSR_KERNEL_GS_BASE, ctxt->usermode_gs_base);
258 #else
259 loadsegment(gs, ctxt->gs);
260 #endif
261
262 do_fpu_end();
263 tsc_verify_tsc_adjust(true);
264 x86_platform.restore_sched_clock_state();
265 cache_bp_restore();
266 perf_restore_debug_store();
267
268 c = &cpu_data(smp_processor_id());
269 if (cpu_has(c, X86_FEATURE_MSR_IA32_FEAT_CTL))
270 init_ia32_feat_ctl(c);
271
272 microcode_bsp_resume();
273
274 /*
275 * This needs to happen after the microcode has been updated upon resume
276 * because some of the MSRs are "emulated" in microcode.
277 */
278 msr_restore_context(ctxt);
279 }
280
281 /* Needed by apm.c */
282 void notrace restore_processor_state(void)
283 {
284 __restore_processor_state(&saved_context);
285 }
286 #ifdef CONFIG_X86_32
287 EXPORT_SYMBOL(restore_processor_state);
288 #endif
289
290 #if defined(CONFIG_HIBERNATION) && defined(CONFIG_HOTPLUG_CPU)
291 static void __noreturn resume_play_dead(void)
292 {
293 play_dead_common();
294 tboot_shutdown(TB_SHUTDOWN_WFS);
295 hlt_play_dead();
296 }
297
298 int hibernate_resume_nonboot_cpu_disable(void)
299 {
300 void (*play_dead)(void) = smp_ops.play_dead;
301 int ret;
302
303 /*
304 * Ensure that MONITOR/MWAIT will not be used in the "play dead" loop
305 * during hibernate image restoration, because it is likely that the
306 * monitored address will be actually written to at that time and then
307 * the "dead" CPU will attempt to execute instructions again, but the
308 * address in its instruction pointer may not be possible to resolve
309 * any more at that point (the page tables used by it previously may
310 * have been overwritten by hibernate image data).
311 *
312 * First, make sure that we wake up all the potentially disabled SMT
313 * threads which have been initially brought up and then put into
314 * mwait/cpuidle sleep.
315 * Those will be put to proper (not interfering with hibernation
316 * resume) sleep afterwards, and the resumed kernel will decide itself
317 * what to do with them.
318 */
319 ret = cpuhp_smt_enable();
320 if (ret)
321 return ret;
322 smp_ops.play_dead = resume_play_dead;
323 ret = freeze_secondary_cpus(0);
324 smp_ops.play_dead = play_dead;
325 return ret;
326 }
327 #endif
328
329 /*
330 * When bsp_check() is called in hibernate and suspend, cpu hotplug
331 * is disabled already. So it's unnecessary to handle race condition between
332 * cpumask query and cpu hotplug.
333 */
334 static int bsp_check(void)
335 {
336 if (cpumask_first(cpu_online_mask) != 0) {
337 pr_warn("CPU0 is offline.\n");
338 return -ENODEV;
339 }
340
341 return 0;
342 }
343
344 static int bsp_pm_callback(struct notifier_block *nb, unsigned long action,
345 void *ptr)
346 {
347 int ret = 0;
348
349 switch (action) {
350 case PM_SUSPEND_PREPARE:
351 case PM_HIBERNATION_PREPARE:
352 ret = bsp_check();
353 break;
354 default:
355 break;
356 }
357 return notifier_from_errno(ret);
358 }
359
360 static int __init bsp_pm_check_init(void)
361 {
362 /*
363 * Set this bsp_pm_callback as lower priority than
364 * cpu_hotplug_pm_callback. So cpu_hotplug_pm_callback will be called
365 * earlier to disable cpu hotplug before bsp online check.
366 */
367 pm_notifier(bsp_pm_callback, -INT_MAX);
368 return 0;
369 }
370
371 core_initcall(bsp_pm_check_init);
372
373 static int msr_build_context(const u32 *msr_id, const int num)
374 {
375 struct saved_msrs *saved_msrs = &saved_context.saved_msrs;
376 struct saved_msr *msr_array;
377 int total_num;
378 int i, j;
379
380 total_num = saved_msrs->num + num;
381
382 msr_array = kmalloc_array(total_num, sizeof(struct saved_msr), GFP_KERNEL);
383 if (!msr_array) {
384 pr_err("x86/pm: Can not allocate memory to save/restore MSRs during suspend.\n");
385 return -ENOMEM;
386 }
387
388 if (saved_msrs->array) {
389 /*
390 * Multiple callbacks can invoke this function, so copy any
391 * MSR save requests from previous invocations.
392 */
393 memcpy(msr_array, saved_msrs->array,
394 sizeof(struct saved_msr) * saved_msrs->num);
395
396 kfree(saved_msrs->array);
397 }
398
399 for (i = saved_msrs->num, j = 0; i < total_num; i++, j++) {
400 u64 dummy;
401
402 msr_array[i].info.msr_no = msr_id[j];
403 msr_array[i].valid = !rdmsrl_safe(msr_id[j], &dummy);
404 msr_array[i].info.reg.q = 0;
405 }
406 saved_msrs->num = total_num;
407 saved_msrs->array = msr_array;
408
409 return 0;
410 }
411
412 /*
413 * The following sections are a quirk framework for problematic BIOSen:
414 * Sometimes MSRs are modified by the BIOSen after suspended to
415 * RAM, this might cause unexpected behavior after wakeup.
416 * Thus we save/restore these specified MSRs across suspend/resume
417 * in order to work around it.
418 *
419 * For any further problematic BIOSen/platforms,
420 * please add your own function similar to msr_initialize_bdw.
421 */
422 static int msr_initialize_bdw(const struct dmi_system_id *d)
423 {
424 /* Add any extra MSR ids into this array. */
425 u32 bdw_msr_id[] = { MSR_IA32_THERM_CONTROL };
426
427 pr_info("x86/pm: %s detected, MSR saving is needed during suspending.\n", d->ident);
428 return msr_build_context(bdw_msr_id, ARRAY_SIZE(bdw_msr_id));
429 }
430
431 static const struct dmi_system_id msr_save_dmi_table[] = {
432 {
433 .callback = msr_initialize_bdw,
434 .ident = "BROADWELL BDX_EP",
435 .matches = {
436 DMI_MATCH(DMI_PRODUCT_NAME, "GRANTLEY"),
437 DMI_MATCH(DMI_PRODUCT_VERSION, "E63448-400"),
438 },
439 },
440 {}
441 };
442
443 static int msr_save_cpuid_features(const struct x86_cpu_id *c)
444 {
445 u32 cpuid_msr_id[] = {
446 MSR_AMD64_CPUID_FN_1,
447 };
448
449 pr_info("x86/pm: family %#hx cpu detected, MSR saving is needed during suspending.\n",
450 c->family);
451
452 return msr_build_context(cpuid_msr_id, ARRAY_SIZE(cpuid_msr_id));
453 }
454
455 static const struct x86_cpu_id msr_save_cpu_table[] = {
456 X86_MATCH_VENDOR_FAM(AMD, 0x15, &msr_save_cpuid_features),
457 X86_MATCH_VENDOR_FAM(AMD, 0x16, &msr_save_cpuid_features),
458 {}
459 };
460
461 typedef int (*pm_cpu_match_t)(const struct x86_cpu_id *);
462 static int pm_cpu_check(const struct x86_cpu_id *c)
463 {
464 const struct x86_cpu_id *m;
465 int ret = 0;
466
467 m = x86_match_cpu(msr_save_cpu_table);
468 if (m) {
469 pm_cpu_match_t fn;
470
471 fn = (pm_cpu_match_t)m->driver_data;
472 ret = fn(m);
473 }
474
475 return ret;
476 }
477
478 static void pm_save_spec_msr(void)
479 {
480 struct msr_enumeration {
481 u32 msr_no;
482 u32 feature;
483 } msr_enum[] = {
484 { MSR_IA32_SPEC_CTRL, X86_FEATURE_MSR_SPEC_CTRL },
485 { MSR_IA32_TSX_CTRL, X86_FEATURE_MSR_TSX_CTRL },
486 { MSR_TSX_FORCE_ABORT, X86_FEATURE_TSX_FORCE_ABORT },
487 { MSR_IA32_MCU_OPT_CTRL, X86_FEATURE_SRBDS_CTRL },
488 { MSR_AMD64_LS_CFG, X86_FEATURE_LS_CFG_SSBD },
489 { MSR_AMD64_DE_CFG, X86_FEATURE_LFENCE_RDTSC },
490 };
491 int i;
492
493 for (i = 0; i < ARRAY_SIZE(msr_enum); i++) {
494 if (boot_cpu_has(msr_enum[i].feature))
495 msr_build_context(&msr_enum[i].msr_no, 1);
496 }
497 }
498
499 static int pm_check_save_msr(void)
500 {
501 dmi_check_system(msr_save_dmi_table);
502 pm_cpu_check(msr_save_cpu_table);
503 pm_save_spec_msr();
504
505 return 0;
506 }
507
508 device_initcall(pm_check_save_msr);
509
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